The buses will move delegates, journalists, party officials and others to the Tampa Bay Times Forum from the 105 hotels the convention has booked in Hillsborough, Pinellas and Pasco counties.

The convention originally estimated that 300 buses would do the job but raised the number at the suggestion of its fleet operator, SP Plus Gameday of Orlando.

Each of the 56-seat motor coaches will have at least one law enforcement officer on board.

Police also will stop cross traffic at downtown Tampa intersections as the bus caravans head to or leave the Times Forum, where the GOP will meet from Aug. 27-30 to name its presidential nominee.

The good thing, organizers say, is that with convention sessions starting in the early evening, Tampa's morning rush hour should not see a heavy impact. Rather, buses are expected to start arriving downtown at about 5 p.m. and to leave at about 10 or 11 p.m.

Outside the central business district, local officials have said, setting aside a dedicated charter bus lane on the interstate is possible, though far from certain. Tampa police said last week that the transportation plan for the convention won't be finalized until after the Secret Service sets the security perimeter, expected to happen in July at the earliest.

Under the city's contract with the convention host committee, Tampa must ensure that there's space to park 300 buses "as close as possible" to the convention. Because space around the Times Forum is tight, the location of the parking is expected to have an effect on where the city can create its protest area for demonstrators. Court cases from previous conventions have established that such demonstration areas must be within sight and sound of the convention.

But both convention spokesman James Davis and a top city official said they do not expect the bigger number of buses to affect the discussion about providing parking near the venue. City chief of staff Santiago Corrada said he had not seen the plan for the additional buses but understood that they'll be used more as circulator buses.